Professor David Green


It's not easy being green

PATRICK McDONAGH\ | The songs of frogs resonate across the fields and through our primitive brains, evoking a primeval memory of nature apart from our concrete and steel forests, a remnant of what we have lost. But variations on the theme exist.

Not so long ago, that most famous of frogs, Kermit, sang his own song on The Muppet Show: "It's Not Easy Being Green." For an amphibian, Kermit seems startlingly prophetic -- life in the nineties has been rough on North American amphibian populations.

But amphibians are in a sense prophetic, often being among the first creatures to respond to environmental turmoil, according to biology professor David Green, the Redpath Museum's curator of vertebrates. Green is a widely respected expert on frog populations and what they can tell us, as well as the chair of the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), the agency which assesses plant and animal populations and designates whether or not they are at risk, and if so, how great a risk.

"I knew I was going to be a herpetologist before I knew what the word was," says Green of his interest in amphibians. "I didn't choose them; they chose me. It was love."

Like many people, as a child he caught frogs and toads as pets. "Somehow I managed to make the transfer from caring for these animals as pets, and wanting to study them." By high school, he had metamorphosed into a herpetologist, someone who studies reptiles and amphibians.

According to Green's studies on amphibian populations in Canada, in environmental terms, frogs are similar to the canaries brought into coal mines to warn miners of fumes. If the canary died, the miners knew that they too would perish if they didn't leave. Explains Green: "Frogs live and breathe in water. If it's bad, they'll die before we will. Plus, people like them," he claims. This appeal makes them useful as barometers of environmental decline because people notice a diminishing frog presence. The songs disappear.

Because frog populations are indicators of the environmental health of a region, we should be paying attention to declining regional populations, not just to animals threatened by extinction. "If all the frogs disappeared from Canada, no species would go extinct," Green notes. Every sort of frog that exists in Canada lives somewhere else in the world as well. However, disappearance of regional populations in this country would suggest that problems were taking their toll on the local environments.

"The magic bullet to explain frog decline -- acid rain or ozone depletion, for instance -- does not actually exist," he explains. Rather, he argues, long-term population declines, while a global phenomenon, are the result of local circumstances.

While population variation is the norm for any given locale, in a healthy environment, neighbouring populations exist to help revitalize declining communities. Consider the plight of the northern leopard frog, endangered in British Columbia, but thriving in Manitoba. In British Columbia, a combination of human impact on the environment and geographical features -- mountains and semi-arid regions that isolate habitats -- make it difficult for frog populations to revive. This phenomenon may point to regional patterns of environmental decline that must be considered in any attempts to redress the problem.

Indeed, the fact that frog depletion is a result of specific local factors as opposed to a "silver bullet" such as global warming means people can do something to counter it.

For Green, that something is tied to his activities with COSEWIC. The quasi-governmental agency was created by provincial directors of wildlife in 1977 to consider and designate species at risk. Soon after finishing his doctorate in 1982 at Guelph, Green found himself reporting on toad populations for COSEWIC; later he was offered the chair of the herpetology subcommittee, a position he shares with a reptile specialist; his job is to enlist specialists to research and report on amphibian populations across Canada. This past April, Green was made chair of COSEWIC as well.

COSEWIC works without fanfare to identify those plants and animals that are in some way endangered by humans, and to designate them appropriately; individual researchers submit reports, and based on these reports the committee designates the species either "not at risk" or "at risk." If they are at risk, they must be further designated "vulnerable," "threatened," "endangered," "extirpated" (meaning the species no longer can be found in Canada), or "extinct" (if the species no longer exists).

Although governments can ignore these designations as they are not legally binding, COSEWIC prefers it thus, resisting a recent move to give their designations legal weight. "As soon as the list is legal, COSEWIC is a legislating body," Green explains, "and Pandora's box opens. We would end up with the same problems they have in the States, where designating species to an endangered list is an excruciating political process requiring an act of Congress."

As things stand now, COSEWIC has the power to publish its list before sending it to the minister, giving it a media presence while retaining its independence. "Most cases do not pose a political problem," says Green. "For those where commercial or cultural interests are involved, there are problems. Then the process enters into the sphere of politics, which is why we pay politicians."

COSEWIC's arm's-length status made it possible for it to include controversial species on its 1998 lists; the north Atlantic cod, for instance, is listed as "vulnerable" and the sage grouse, a popular game bird on the prairies, is endangered (and extirpated in British Columbia). With COSEWIC as a legislative body, argues Green, there would be so much political interference that such designations would never be made. "Instead, we have the luxury of dealing with it on a scientific balance alone."

But the work is more than a scientific endeavour for Green. Strip away his research credentials, his publications, and his environmental activism and David Green is, at heart, a man very much enamoured with his subject. Should Kermit be right, and it isn't easy being green, David Green certainly makes it seem worth the effort.

The Redpath Museum will host a conference on extinction and endangered species beginning October 2. Green will speak, as will biology professor Amanda Vincent, the world's top expert on seahorses, and Professor Peter Brown, the new director of the McGill School of Environment. The conference is sponsored by McGill, COSEWIC and the Canadian Wildlife Service. Call 398-4086 for more information.